package com.heima.admin.gateway.utils;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.CompressionCodecs;
import io.jsonwebtoken.ExpiredJwtException;
import io.jsonwebtoken.Jws;
import io.jsonwebtoken.JwsHeader;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

public class AppJwtUtil {

    // TOKEN的有效期一天（S）
    private static final int TOKEN_TIME_OUT = 3_600;
    // 加密KEY
    private static final String TOKEN_ENCRY_KEY = "MDk4ZjZiY2Q0NjIxZDM3M2NhZGU0ZTgzMjYyN2I0ZjY";
    // 最小刷新间隔(S)
    private static final int REFRESH_TIME = 300;

    /**
     * 生产JWT令牌
     * @param id  只保存用户的ID
     * @return
     */
    public static String getToken(Long id){

        Map<String, Object> claimMaps = new HashMap<>();
        claimMaps.put("id",id);

        long currentTime = System.currentTimeMillis();
        return Jwts.builder()
                .setId(UUID.randomUUID().toString())
                .setIssuedAt(new Date(currentTime))  //签发时间
                .setSubject("system")  //说明
                .setIssuer("heima") //签发者信息
                .setAudience("app")  //接收用户
                .compressWith(CompressionCodecs.GZIP)  //数据压缩方式
                .signWith(SignatureAlgorithm.HS512, generalKey()) //加密方式
                .setExpiration(new Date(currentTime + TOKEN_TIME_OUT * 1000))  //过期时间戳
                .addClaims(claimMaps) //cla信息 用户ID --》 Claims
                .compact();
    }

    /**
     * 获取token中的claims信息
     *
     * @param token
     * @return
     */
    private static Jws<Claims> getJws(String token) {
            return Jwts.parser()
                    .setSigningKey(generalKey())
                    .parseClaimsJws(token);
    }

    /**
     * 获取payload body信息
     *
     * @param token
     * @return
     */
    public static Claims getClaimsBody(String token) {
        try {
            return getJws(token).getBody();
        }catch (ExpiredJwtException e){
            return null;
        }
    }

    /**
     * 获取hearder body信息
     *
     * @param token
     * @return
     */
    public static JwsHeader getHeaderBody(String token) {
        return getJws(token).getHeader();
    }

    /**
     * 校验令牌合法性
     *
     * @param claims
     * @return -1：有效，0：有效，  1：过期，2：过期
     */
    public static int verifyToken(Claims claims) {
        if(claims==null){
            return 1;
        }
        try {
            claims.getExpiration()
                    .before(new Date());
            // 需要自动刷新TOKEN
            if((claims.getExpiration().getTime()-System.currentTimeMillis())>REFRESH_TIME*1000){
                return -1;
            }else {
                return 0;
            }
        } catch (ExpiredJwtException ex) {
            return 1;
        }catch (Exception e){
            return 2;
        }
    }

    /**
     * 由字符串生成加密key
     *
     * @return
     */
    public static SecretKey generalKey() {
        byte[] encodedKey = Base64.getEncoder().encode(TOKEN_ENCRY_KEY.getBytes());
        SecretKey key = new SecretKeySpec(encodedKey, 0, encodedKey.length, "AES");
        return key;
    }

    public static void main(String[] args) {
       /* Map map = new HashMap();
        map.put("id","11");*/
        System.out.println(AppJwtUtil.getToken(1102L));
//        Jws<Claims> jws = AppJwtUtil.getJws("eyJhbGciOiJIUzUxMiIsInppcCI6IkdaSVAifQ.H4sIAAAAAAAAADWL0QqDMAwA_yXPFoyLNfVvUhtZB0IhFTaG_774sLc7jvvCq1dYoWwxU9w0ZCEKxHMKSR5LiJp2LsiKUmCAKh1WjDjzEiekAezMftvHuh53N3N9aj3ETc7iJq0567v9z8T3Wb0hjtP1A6yM_t-DAAAA._Qm7BV9LHZD1jOyYDJe7wIJCW6CZjMMZorG3lM9RZGGEQ2wl_fpEzZdtEx3sg-ZZLia5HoE2VuKbJSkvc1kwnQ");
//        Claims claims = jws.getBody();
//        System.out.println(claims.get("id"));
        Claims claims = AppJwtUtil.getClaimsBody("EyJhbGciOiJIUzUxMiIsInppcCI6IkdaSVAifQ.H4sIAAAAAAAAADWL0QqDMAwA_yXPFoyLNfVvUhtZB0IhFTaG_774sLc7jvvCq1dYoWwxU9w0ZCEKxHMKSR5LiJp2LsiKUmCAKh1WjDjzEiekAezMftvHuh53N3N9aj3ETc7iJq0567v9z8T3Wb0hjtP1A6yM_t-DAAAA._Qm7BV9LHZD1jOyYDJe7wIJCW6CZjMMZorG3lM9RZGGEQ2wl_fpEzZdtEx3sg-ZZLia5HoE2VuKbJSkvc1kwnQ");
        System.out.println(claims.get("id"));

        System.out.println(AppJwtUtil.verifyToken(claims));

    }

}
